Ratchet bar push structure of grease gun

ABSTRACT

A ratchet bar push structure of grease gun includes a gun body and a grease storage section. A ratchet bar is slidably disposed in the gun body and reciprocally movable as a piston to dispense grease supplied by the grease storage section out of the gun body. A pad section is movably disposed between the ratchet bar and a push member for pushing the ratchet bar as a force transmission unit. A user can change the position of the pad section to control whether an action force of the push member is transmitted to the ratchet bar. When the pad section is positioned in a padded position, the external force is applied to the ratchet bar via the pad section to push the ratchet bar. When positioned in a released position, the force transmission path is interrupted, whereby the ratchet bar will not be pushed by the push member.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a grease-dispensing device,and more particularly to a ratchet bar push structure of a grease gun.

2. Description of the Related Art

A conventional grease gun is used to dispense grease to a work piece forproviding lubrication or antirust effect. The traditional grease gun canonly discharge a constant amount of grease. This often fails to meet therequirement of actual operation. For overcoming this problem, U.S.Publication No. 2009/0272762 A1 discloses a two-stage grease gun, whichcan be operated to dispense different amounts of grease in ahigh-pressure low-flow mode or a low-pressure high-flow mode inaccordance with the requirements of actual situations.

To speak more specifically, the two-stage grease gun of the above patentemploys two grease-pushing ratchet bars with different diameters, whichcan move within piston chambers as pistons. In the low-pressurehigh-flow mode, the large-diameter grease-pushing ratchet bar is movedwithin the piston chamber to dispense the grease out of the grease gun.In the high-pressure low-flow mode, the small-diameter grease-pushingratchet bar is moved within the piston chamber to dispense the greaseout of the grease gun. In the structures of the above patent, a usermust apply a force to both the large-diameter grease-pushing ratchet barand the small-diameter grease-pushing ratchet bar to reciprocally movethem as pistons for dispensing the grease. When the backpressure appliedto the grease is greater than the discharge pressure of thelarge-diameter grease-pushing ratchet bar, the grease pushed by thelarge-diameter grease-pushing ratchet bar will flow back into the greasereservoir through a flow bypass. Under such circumstance, only thegrease pushed by the small-diameter grease-pushing ratchet bar isdispensed out of the grease gun. Accordingly, the grease gun can beoperated to dispense different amounts of grease in different flow modesin accordance with the requirements of different situations.

The above two-stage grease gun with flow bypass can be operated in twodifferent flow modes to dispense different amounts of grease. However,in structure, it is necessary to additionally dispose a flow bypass inthe piston chamber within which the grease-pushing ratchet bar is movedfor the grease to flow back to the grease reservoir. The flow bypassmust have a check function. Accordingly, the structure of such greasegun is more complicated and hard to assemble. Moreover, in both flowmodes, when pushing and dispensing the grease out of the grease gun, theuser must push the respective grease-pushing ratchet bars at the sametime to make them synchronously reciprocally move as pistons. Therefore,it costs much strength to operate the grease gun.

SUMMARY OF THE INVENTION

It is therefore a primary object of the present invention to provide aratchet bar push structure of a grease gun. By means of the ratchet barpush structure, a user can operate the grease gun to dispense grease intwo different flow modes with less strength.

It is a further object of the present invention to provide the aboveratchet bar push structure of the grease gun, which is simplified and iseasy to process and assemble.

To achieve the above and other objects, the ratchet bar push structureof the grease gun of the present invention includes a gun body; a greasestorage section for storing grease; a fitting section disposed in thegun body and having at least one cylindrical piston chamber, the fittingsection being formed with an incoming flow passage in communication withone side of the piston chamber, the incoming flow passage being spacedfrom one end of the piston chamber for communicating the grease storagesection with the piston chamber; a ratchet bar coaxially slidablydisposed in the piston chamber, the ratchet bar having a diameter equalto an inner diameter of the piston chamber; and a push member connectedto one end of the ratchet bar, which end extends out of the pistonchamber for pushing the ratchet bar to axially move within the pistonchamber. The ratchet bar push structure is characterized in that thepush member has an end section and a slide section positioned betweenthe end section and the end of the ratchet bar, whereby the ratchet baris slidable along the slide section relative to the end section. Theratchet bar push structure further includes a pad section movablebetween a padded position and a released position. When positioned inthe padded position, the pad section is positioned between the end ofthe ratchet bar and the end section, whereby when an external force isapplied to the end section, the end section can push the ratchet bar viathe pad section and make the ratchet bar synchronously move with the endsection. When positioned in the released position, the pad sectionreleases the end of the ratchet bar, whereby the ratchet bar is slidablealong the slide section relative to the end section without being pushedby the end section.

The present invention can be best understood through the followingdescription and accompanying drawings, wherein:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a preferred embodiment of the presentinvention;

FIG. 2 is a perspective view of a part of the preferred embodiment ofthe present invention;

FIGS. 3 and 4 are partially sectional views of the preferred embodimentof the present invention, showing that the pad section is positioned inthe released position and only the second ratchet bar is moved as apiston;

FIGS. 5 and 6 are partially sectional views of the preferred embodimentof the present invention, showing that the pad section is positioned inthe padded position and both the first and second ratchet bars are movedas pistons;

FIG. 7 is a sectional view taken along line a-a of FIG. 3;

FIG. 8 is a sectional view taken along line b-b of FIG. 5;

FIG. 9 is a perspective view of a part of another preferred embodimentof the present invention;

FIG. 10 is an end view of the other preferred embodiment of the presentinvention, showing that the pad section is positioned in the releasedposition; and

FIG. 11 is an end view of the other preferred embodiment of the presentinvention, showing that the pad section is positioned in the paddedposition.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer to FIGS. 1 to 8. According a preferred embodiment, theratchet bar push structure 10 of grease gun of the present inventionincludes a gun body 20, a grease storage section 30, a fitting section40, a first ratchet bar 50, a second ratchet bar 60, a push member 70and a pad section 80.

The gun body 20 and the grease storage section 30 both pertain to priorart and thus will not be further described hereinafter.

The fitting section 40 is disposed in the gun body 20 and has acylindrical fitting body 41 with a certain length. The fitting body 41is formed with a first cylindrical piston chamber 42 and a secondcylindrical piston chamber 43 in parallel to each other. The first andsecond piston chambers 42, 43 axially inward extend from one end of thefitting body 41 by a certain depth. An elongated incoming flow passage44 is formed through one side of the fitting body 41 in communicationwith one side of the first piston chamber 42 and one side of the secondpiston chamber 43. The incoming passage 44 communicates the first andsecond piston chambers 42, 43 with an internal grease reservoir of thegrease storage section 30. The first piston chamber 42 has an innerdiameter larger than that of the second piston chamber 43.

The first ratchet bar 50 is coaxially slidably disposed in the firstpiston chamber 42 and is reciprocally movable within the first pistonchamber 42 as a piston. The first ratchet bar 50 has a main bar body 51coaxially slidably disposed in the first piston chamber 42. The main barbody 51 has a diameter equal to the inner diameter of the first pistonchamber 42. A rectangular end piece 52 with a noncircular cross sectionis fixedly connected to an end of the main bar body 51, which endextends out of the first piston chamber 42. The end piece 52 axiallyextends from the end of the main bar body 51. The end piece 52 has aminimum outer diameter smaller than the diameter of the main bar body51.

The second ratchet bar 60 is coaxially slidably disposed in the secondpiston chamber 43 and is reciprocally movable within the second pistonchamber 43 as a piston. The second ratchet bar 50 has a diameter equalto the inner diameter of the second piston chamber 43. One end of thesecond ratchet bar 60 extends out of the second piston chamber 43.

The push member 70 has an end section 71 and a slide section 72. One endof the slide section 72 is connected to the end section 71, while theother end of the slide section 72 is coaxially slidably connected to oneend of the first ratchet bar 50, whereby the first ratchet bar 50 isreciprocally extensibly/retractably slidable relative to the end section71.

To speak more specifically, the end section 71 is substantially in theform of a plate and is perpendicularly fixedly connected to the secondratchet bar 60. The end section 71 is also connected to the firstratchet bar 50 via the slide section 72. Accordingly, a user can press apress lever 21 of the gun body 20 against the end section 71 forforcedly moving the first and second ratchet bars 50, 60.

The slide section 72 has a slide rod 721. One end of the slide rod 721is fixedly connected to the end section 71. The end piece 52 is formedwith a slide socket 722 inward extending from a free end of the endpiece 52 by a certain length into the main bar body 51. The slide rod721 is coaxially slidable fitted in the slide socket 722.

The pad section 80 is a block body 81 with a certain thickness. One faceof the pad section 80 is attached to a face of the end section 71. Theblock body 81 is rotatably connected with the slide rod 721, whereby theblock body 81 is rotatable around an axis of the slide rod 721 between apadded position and a released position. The other face of the blockbody 81 is recessed to form a notch-like receiving space 82 with a shapecomplementary to the cross-sectional shape of the end piece 52. Thereceiving space 82 inward extends from the other face of the block body81. When the block body 81 is positioned in the released position, anopening of the receiving space 82 correspondingly complementarily facesthe free end of the end piece 52. Under such circumstance, the end piece52 can be slid through the opening of the receiving space 82 into thereceiving space 82. When the block body 81 is positioned in the paddedposition, the opening of the receiving space 82 crosses the free end ofthe end piece 52. Under such circumstance, the end piece 52 cannot befitted into the receiving space 82 and the end face of the free end ofthe end piece 52 abuts against the other face of the block body 81.

According to the above arrangement, a user can selectively operate theratchet bar push structure 10 of the grease gun in a double-flowdischarge mode. To speak more specifically, when it is necessary todispense a large amount of grease, a user can position the pad section80 in the padded position where the block body 81 is sandwiched betweenthe free end of the end piece 52 and the end section 71. In this case,when the user applies a force to the press lever 21, the end section 71not only drives the second ratchet bar 60 fixedly connected to the endsection 71 to move within the second piston chamber 43 as a piston, butalso forces the end piece 52 via the pad section 80 to drive the firstratchet bar 50 to move within the first piston chamber 42 as a piston.Accordingly, the grease contained in the first and second pistonchambers 42, 43 can be synchronously pushed out and dispensed by a largeamount.

In the case that only a small amount of grease needs to be dispensed,the user only needs to shift and rotate the block body 81 with a fingerfrom outer side and make the block body 81 move from the padded positionto the released position. At this time, when applying a force to thepress lever 21, only the second ratchet bar 60 fixedly connected withthe end section 71 can be moved to dispense a smaller amount of grease.In the meantime, with respect to the first ratchet bar 50, the endsection 71 does not abut against the end of the first ratchet bar 50.Therefore, even if the end section 71 is pressed by the press lever 21to move, the end piece 52 can only extend into the receiving space 82 bya different depth without making the first ratchet bar 50 axiallyreciprocally move as a piston.

Accordingly, a user can control the amount of the grease dispensed fromthe grease gun in accordance with the actual requirement. In comparisonwith the conventional technique, by means of the ratchet bar pushstructure 10 of grease gun of the present invention, when dispensing thegrease in the small-amount mode, it is unnecessary to apply a force tothe first ratchet bar 50 to move the same. Therefore, in comparison withthe conventional technique, when using the grease gun of the presentinvention to dispense grease, much strength is saved. Moreover, instructure, the present invention is free from any flow bypass as in theconventional technique so that it is easier to process and assemble thepresent invention.

In the above structure, a user needs to operate and rotate the blockbody of the pad section from outer side and make the block body movebetween the padded position and the released position. However, in theabove embodiment, only a very small part of the block body is exposed tothe outer side. Therefore, it is inconvenient for a user to operate theblock body. To overcome this shortcoming and facilitate the operation ofthe user, FIGS. 9 to 11 show another preferred embodiment of the presentinvention in which an edge of the end section 71′ of the push member 70′is formed with an arched notch 711′ with a certain length. In addition,the pad section 80′ has a first extension section 811′ axially extendingfrom one end of the block body 81′ across into the notch 711′ by acertain length. Accordingly, on one hand the area of the exposed part ofthe block body 81′ is increased to facilitate the operation of the userand on the other hand the first extension section 811′ is restrictedwithin the notch 711′ so as to restrict the block body 81′ to onlyrotate between the padded position and the released position.

Certainly, in order to make the operation more convenient, the size ofthe forced part can be further enlarged. Therefore, in this embodiment,the pad section 80′ further has a second extension section 812′ outwardperpendicularly extending from an end of the first extension section811′. In this case, the user can more conveniently operate the padsection 80′.

The above embodiments are only used to illustrate the present invention,not intended to limit the scope thereof. Many modifications of the aboveembodiments can be made without departing from the spirit of the presentinvention.

1. A ratchet bar push structure of grease gun, comprising: a gun body; agrease storage section for storing grease; a fitting section disposed inthe gun body and having at least one cylindrical piston chamber, thefitting section being formed with an incoming flow passage incommunication with one side of the piston chamber, the incoming flowpassage being spaced from one end of the piston chamber forcommunicating the grease storage section with the piston chamber; aratchet bar coaxially slidably disposed in the piston chamber, theratchet bar having a diameter equal to an inner diameter of the pistonchamber; and a push member connected to one end of the ratchet bar,which end extends out of the piston chamber for pushing the ratchet barto axially move within the piston chamber, the ratchet bar pushstructure being characterized in that the push member has an end sectionand a slide section positioned between the end section and the end ofthe ratchet bar, whereby the ratchet bar is slidable along the slidesection relative to the end section, the ratchet bar push structurefurther comprising a pad section movable between a padded position and areleased position, when positioned in the padded position, the padsection being positioned between the end of the ratchet bar and the endsection, whereby when an external force is applied to the end section,the end section can push the ratchet bar via the pad section and makethe ratchet bar synchronously move with the end section, when positionedin the released position, the pad section releasing the end of theratchet bar, whereby the ratchet bar can slide along the slide sectionrelative to the end section without being pushed by the end section. 2.The ratchet bar push structure of the grease gun as claimed in claim 1,wherein the slide section has a slide rod, one end of the slide rodbeing fixedly connected to the end section, the end of the ratchet barbeing formed with a slide socket inward axially extending from the endof the ratchet bar by a certain depth, the slide rod being coaxiallyslidable fitted in the slide socket.
 3. The ratchet bar push structureof the grease gun as claimed in claim 2, wherein the ratchet bar has amain bar body, the main bar body having a diameter equal to the innerdiameter of the piston chamber, an end piece with a noncircular crosssection being fixedly connected to an end of the main bar body, the endpiece extending from the end of the main bar body along an axis of themain bar body, the end piece having a minimum outer diameter smallerthan the diameter of the main bar body.
 4. The ratchet bar pushstructure of the grease gun as claimed in claim 3, wherein the padsection is a block body, one face of the block body being attached tothe end section, the block body being rotatably connected with the sliderod, whereby the block body is rotatable around an axis of the slide rodbetween the padded position and the released position, the other face ofthe block body being recessed to form a receiving space with a shapecomplementary to the cross-sectional shape of the end piece, thereceiving space inward extending from the other face of the block bodyby a certain depth, whereby when the block body is positioned in thereleased position, an opening of the receiving space correspondinglycomplementarily faces the end piece, permitting the end piece to slidethrough the opening of the receiving space into the receiving space,while when the block body is positioned in the padded position, theopening of the receiving space crosses a free end of the end piece sothat the end piece cannot be slid into the receiving space through theopening thereof and an end face of the free end of the end piece abutsagainst the other face of the block body.
 5. The ratchet bar pushstructure of the grease gun as claimed in claim 4, wherein the end piecehas a substantially rectangular cross section and the receiving spacehas the form of a notch corresponding to the end piece.
 6. The ratchetbar push structure of the grease gun as claimed in claim 4, wherein theend section of the push member is formed with a notch and the padsection has a first extension section outward extending from the blockbody across into the notch.
 7. The ratchet bar push structure of thegrease gun as claimed in claim 6, wherein the pad section further has asecond extension section outward extending from the first extensionsection.